After a fight Hayate, Nagi heads to the apartment complex to hang out.  But her “little sister” is the only one home.  This might be Nagi’s chance to find out what Ruri’s real goal is. 
Mommy, why did you marry Daddy?
Mamá, ¿por qué te casaste con papá?
Mamá, ¿por qué te casaste con papá?
Mamãe, por que você
se casou com o papai?